Unloader for forming machines



NOV. 8, 1932. w|TTE 1,886,458

UNLOADER FOR FORMING MACHINES Filed April 21, 1932 4 sheets-sheet 1 INVENTOR Z2404 WTTE.

2W5; Haw/wk ATTORN EYS Nov. 8, 1932. P. WlTTE UNLOADER FOR FORMING MACHINES Filed April 21, 1932 4 Sheets-Sheet 2 INVENTOR B401; WTTE.

BY I W H ATTORNEYS Nov. 8, 1932. P. WlTTE 'UNLOADER FOR FORMING MACHINES Filed April 21,' 1952 4 Sheets-Sheet 3 INVENTQR 71 7 ATTQRN EYS P. WlTTE UNLOADER FOR FORMING MACHINES Nov. 8, 1932.

Filed April 21, 1932 4 Sheets-Sheet 4 INVENTOR PA (/L W/ T75.

ATTORNEYS Patented Nov. 8, 1932 UNITED STATES PATENT QFFICE PAUL WITTE, OF NEW MILFORD, NEW JERSEY, ASSIGNOR T WHITE METALSMANUFiLC TUBING COMPAIJY, OF HOBOKEN, NEW JERSEY, A CQR-PORATEON OF NEW JERSEY UNLOADER FOR FORMING MACHINES Application file'd April 21,

This invention relates to means for automatically removing articles from forming machines such as presses which employ cooperating die and plunger adapted to form an article by extrusion from a disc-like blank.

In the manufacture of collapsible tubes such as those used for tooth paste, shaving cream, oil paints and the like, the tubes are usually made of extremely soft and ductile metal such as white metal, tin, lead and the like. Known types of presses are used in the formation of such tubes. These employ a fixed die adapted to receive .a blank and a cooperating plunger or punch carried by a l vertically reciprocating and horizontally swingable arm. On its down-stroke, the

punch engages a blank in the die and by extrusion the soft metal disc is formed into an elongated tube. After the. tube is formed, the punch is elevated and the arm carrying it swings outwardly so as to permit removal of the tube- Originally, the tubes were removed from the punch by hand. Later, unloading devices were devised.

In one form, of unloading device a jet of air was employed to remove the formed tube from the plunger.

In another known form of device, jaws were provided which embrace the upper portion of the punch and were arranged so as to push downwardly against the edge of the formed tube so as to strip it from the punch. These known forms of unloaders possess disadvantages which my present invention aims to overcome. With the pneumatic type of unloader, some sort of an air pump or air supply is required and this air must be conveyed to the center of the punch, which is carried by moving This usually involves the use of a flexible connection which is apt to develop leaks and cause either irregular operation or actual failure of the ejecting function. Timed air valves are also required in the pneumaticsystem. These require frequent attention and if air leaks develop, proper operation, of the unloading mechanism is interfered with. If the formed tube is not elected at the proper time it will be understood that when the punch returns to its operative position in. lLS normal cycle of opera- 1932. Serial No. 606,599.

tion to produce another tube, the previously formed tube will still be on the punch. 7 This will cause a jambing of the machine and necessitate a temporary shut down to per mit the removal of material. avoided in the interest of economy.

In the mechanical type of unloader heretofore used wherein the tube is pushed from the punch, the unloading mechanism was carried by a swinging arm and employed semi-V cooperating sleeve-like members circular which embrace the punch periodically and move longitudinally thereof so as to push against the upper edge of the formed tube. Such a device possesses certain inherent disadvantages. First, the extruded tubes when formed on the punch are not square ended due to the very nature of the extruding opera tion, thus, the pushing sleeves do not make even contact all around with the upper edge of the formed tube. tube is merely in the neighborhood of 1/100 of an inch. This affords very little edge area to push against; Moreover, the softness or ductility of the stock makes it undesirable to move the tube by pushing action because of the tendency to distort the end of the tube.

In both the pneumatic and mechanical types of unloaders heretofore used, so far as I am aware, there has been no special provision for influencing the direction of travel of the tube after it was released from the punch. My improved mechanism herein dis closed aims to and practice has demonstrated actually does overcome the above and other objections of the prior devices.

My improved apparatus provides means for positively gripping the neck of a formed tube and means for moving the gripping device longitudinally of the punch so as. to strip the tube therefrom and as the grippers approach the end of their stripping move ment, they are automatically disengaged from the tube and the latter is positively freed from. the bite of the grippers and it is given a push. by knockout mechanism so as to influence its direction of travel so as to facilitate carrying off finished tubes-in a deter mined direction. The mechanism is all mounted in a self contained unit or housing This is to be The thickness of the which is so arranged that its position relative to the punch can be readily adjusted so that the unloading unit can be mounted for operation on standard tube-forming machines. And because of the adjustable mounting any given unit can be used on the machine for making tubes of different diameters. These and other features of the invention will be fully apparent from the following specification and the novel features will be pointed out with particularity in accordance with the the statutes in the appended claims.

In the drawings Fig. 1 is a front elevation of a forming mav chine illustrating one embodiment of my invention applied thereto;

Fig. 2 is a horizontal section on line 2,-2 of Fig. 1;

'Fig. 3 is a fragmentary elevation with parts sectioned 05 on line 33 of Fig. 1;

Fig. 4 is an enlarged longitudinal vertical section through my improved unloading unit Fig. 5 is a section on line 5-5 of Fig. 4;

Fig. 6 is a horizontal section on line 6-6 of Fig. 4;

Fig. 7 is a detail View illustrating the manner in which the grippersof my apparatus bite or engage the neck of a formed tube;

Fig. 8 is a view similar tothe upper por tion of Fig. 5, but showing the position which certain parts assume when the grippers initially engage the neck of the formed tube;

Figs. 9, 10, 11, 12 and 13 are horizontal sections on the correspondingly numbered lines of Figs. 8 and 11.

Referring in detail to the drawings, 10 represents a frame of a known type of punch press which carries a reciprocating cross head 12 actuated'by crank pin 14 secured to cranks 16 carried by the main shaft 18 which is driven by a gear 20 from a main driving pinion 22. The cross head carries a horizontally swingable arm 24 from which depends a plunger or punch 26 adaptedtocoact with a suitable die 28 carried by a die holder 30 mounted on the bed or frame of the machine. Disc-like work blanks B (Fig. 2)-are supplied from a magazine 32 through a suitable guide chute 34. These blanks being fed to the die by a reciprocating plunger 36, shown in Fig. 2.

' On the downstroke of thecross head, the plunger 26 cooperating with the die 28 forms or extrudes a tube such as indicated at T.

The metal of this tube flows upwardly and embraces the plunger or punch 26. This method of extrusion on a tube forming machine is well known and will not be further described except to say that upon each downstroke a tube is formed on the plunger. Upon the upstroke, the arm 24 swings outwardly to the position indicated in full lines in Fig. 2 and stays there for a sufiicient length of time to permit the removal of the tube T.

My invention resides in the specific improved means for removing the tube and the combination of such means with the punch or plunger 26 and the swingingv arm 24 of the forming machine, as will more fully hereinafter appear.

The improved unloader is a self contained unit, parts of which are illustrated in Figs. 4 to 13 inclusive. The mechanism includes grippers which are arranged to grasp or bite the neck of the formed tube and then to move longitudinally'of the plunger so as to strip the formed article therefrom. Upon the release of the article from the plunger, the grippers are automatically opened to free the article, whereupon an ejector comes into play to positively free the tube fromthe' grippers. At about the same time, a knock-off mecha nism strikes a blow on part of the tube so as to influence its direction of travel as it falls from the grippers. r

The principal parts of the unloading unit are mounted in the housing 38 which, in the embodiment shown,'is of substantially tubular form. This housing has a cap 40 at the top carrying a stud 42, Fig. 2, whichis connected by a link 44 one end of which is in threaded'engagement with a block 45 pivotally secured to one arm 46 of a bracket 48 secured to the main frame of the machine 10. Another arm 50 of this bracket carries a pivoted. block 52 to the end of which is threaded'a'second link 54. Nuts 55 are provided for adjusting'the effective length of the link 54. By this means, the relative position between the housing and the unloading mechanism carried thereby, and the reciprocating swingable plunger 26 can be readily adjusted, Such adjustment is desirable because it enables the use of one standard me'chamsm" on tube machines for making tubes of different diameters. v

By suitable manipulation of the links 44 and 54, it will be understood that the position of the housing 38 can be accurately adusted.. When this adjustment is secured, a bottom supporting member 56 is fitted and "secured to the frame 10 by nuts 57 passine' through suitable slots in the member 56.

Within the housing 38, I provide longitudinally extending guide rods 58 which form slidable guides fora carriage 60 to which the grippers 62-62 are pivotally secured by means of shouldered journal studs 64. Each gripper comprises a jaw portion 66 which is sharpened to the tapered formation, as indicatedin Fig. so as to provide a cont-acting surface of restricted area which is adapted to graspor bite the neck 68 of the tube T can,

ried by the plunger or punch 26. At the opposite extremity of each gripper, there is pro-. vided a roller 7 O which is adapted to cooperate with a gripper operating bar 7 2. This bar is of substantially triangular shape in.;-

cross section as shown,

for example, in Fig.

6, and the rollers are of cone-like form. A light compression spring 74 is housed in suitable sockets formed in the gripper members and normally tends to close the grippers. But, this spring is not intended to exert a sufficient force to securely hold the neck of the tube in the bite of the grippers. Such secure holding is effected by the movement of the gripper operating bar 7 2. This bar is pivoted at 7 6 (Fig. 11) to a clevis fitting 7 8 secured to the wall of the housing and a compression spring 80, normally tends to rock the operating bar to the position shown in Fig. 4.

The free end 82 of a lever 84 pivoted at 86 coacts with the free end of the operating bar 72 and serves to rock the bar from the gripper release position of Fig. 4 to the gripper holding position of Fig. 8. The lever 84 is rocked by member 88 carried by the swingable arm 24 which carries the punch or plungr 26. This member 88, as clearlyshown in Fig. 4, has an inclined surface which coacts with an anti-friction ball bearing 90 which is adjustably secured by threaded stud 92 to a fitting 94 carried by the upper end of the lever 84. As the swinging arm 24 moves up with the cross head which supports it, the inclined surface of the member 88 exerts a camm g action on the ball bearing 90, thus swinging the lever 84 from the position of 4 to the position indicated in Fig. 8. At the same time, the arm 24 moves up, the carriage 60 also moves upwardly, thus elevating the grippers 62 from the position of 4 to the position of Fig. 8, where they are brought into proper register to grip the neck 68 of the tube. Upward movement of the gripper supporting carriage is limited .ey an adjustable stop which, as shown, in Figs. 4 and 8, consists of a threaded rod 96 having a suitable lock member 98 for looking it in i s adjusted position. During the upward movement of the grippers from the position of Fig. 5 to the position of Fig. 8, they are held open by resilient opener mem ers 100100. he force of these members 5 overcome when the operating rod 72 moves nward to he gripper closing position of Figs. 8 and 9.

The gripper supporting carriage receives its motion through a link 102 connected at one end to the pivot fitting 104 secured to the underside of the carriage and at the other end to fitting 106 pivoted to a lever 108, which in turn is fulcrumed at 110 to a suitable bracket carried by the machine. The lever 108 is connected by link 112 with an arm 114 fulcrumed at 116 to the frame of machine. This arm is provided with cam roller 118 coacting with 120 secured to the shaft 18 of the tube f rming macl'iine. Through these connections, the movements of the pper supporting carriage are accurately synchronized with the movements of the swinging arm 24 and the plunger or punch a sufiicient distance so as to transmitsufiicient movement to link 112, lever 108 and link 102 to pull or strip the tube T'from the plunger or punch 26. The upward movement of the carriage is efiected by the tension spring 109 connected to the lever 108 and to a suitable spring anchorage. Near the end of the downstroke of the gripper carrying carriage, the grippers engage a rod 122, the top of which is pointed and rounded, as indicated at 124, in Fig. 11.

The rod exerts a wedging action, thus forcing the grippers apart or opening them so that they move from the position illustrated in Figs. 9 and 10 to the open position of 12. In this position, under normal conditions, the tube would be naturally expected to be free from tl e bite of the gripper. However, remembering that the articles being handled are made of soft stock such as-lead. ductile tin or white metal, it will be appreciated that there may be a tendency for the neck of the tube to stick to one of the jaws, this being especially true where the jaws exert a firm bite on the material and perhaps become slightly indented on the neck of the tube. For these reasons, I consider it important to provide means for positively disengaging the tube or other formed article from the grippers. For this purpose, 1 pro vide an ejector, which may conveniently take the form illustrated in Fig. 11, at 126. Preferably, though not necessarily, this ejector is provided with an inclined or pointed portion 128 which is adapted to enter the space between the grippers. As thus arranged, it will be apparent that if the tube has a tendency to stick to any one of the grippers, continued movement will bring about a camming action between the tube and the ejector 26, thus positively freeing the tube from the grippers. The ejector is preferably adjustably pivoted by means of a screw 130 to a bracket 132 having a slotted shank 134 by means of which the bracket is adjust-ably secured to an outwardly extending lug 136 secured to the housing 38.

It is important in an unloading mechanism, which strips the tubes from the plunger with a pulling motion, that means be pro vided for positively influencing the direction of travel of the tube as it falls free of the grippers. For this purpose, I provide, what I term, a knock-off mechanism. This mechanism includes a spring-like finger or a yielding member 138, the lower end of which is offset and secured to the carriage by means of a su'table fastening device 189. When the grippers are in their uppermost position, the knock-off finger 138 lies substantially par allel to and adjacent the tube and in close Cil proximity thereto. This relationship exists during the downward movement of the carriage. But, about the time the grippers begin to open, wing-like extensions 1% formed on the knock-oft finger 138 come into engagement with the cam-like inclined surfaces 142 of cam bars 1% secured to the exterior or" the housing 38. Thus continuing downward movement of the carriage flexes the knockoff finger 138, for example,- from the position of Fig. 8 to the position shown in Fig. 11. The result of this, of course, is to impart a quick movement to the tube transversely of its initial direction of travel. This of course influences the ultimate-direction of travel of the tube and insures its falling from the grippers in a controlled direction so that it will properly tall either onto a suitable belt conveyor or to an inclined chute, or receptacle, as shown. 1

From the foregoing, it will be clear that my improved unloading mechanism provides means for positively gripping the neck of a formed tube or similar article and for pulling it from the punch with a tension pull as contrasted with a compressive force such as heretofore employed in machines of similar character which push the tube by an edge contact or in that type of machine in which the tube is forced'from the plunger by air pressure. The gripping mechanism clescribed is so designed that the work is grasped forcibly a the point on the article where the stock is relatively heavy. :The gripping jawsare so shaped, as indcated in Fig. 7, that the point oi contact with the work is in the immediatezone where the neck 68 of the tube joins the inclined shoulder portion leading to the cylindricalpart of the tube. This is oi advantage because any roughening that may result from the gripping ofthe tube will make little or no dinerence in its final value because the point of such roughening will be at a location which is at the end of the screw threads-which are subsequently formed upon tubes of this character.

While I have described quite precisely the details of the embodiment of the invention herein illustrated, it is to be understood that the description and drawings are to be interpreted in an illustrative rather than limiting sense since variousmodifications may be made by those skilled in the art without departure from the invention as defined in the appended claims.

What I claim is 1. A press for making collapsible tubes of soft metal, comprising a laterally swinging arm carrying a plunger arranged to be reciprocated longitud nally, grippers adapted to grasp the neck on the extremity of a tube caried by the plunger punch, a carriage movable along stationary guides and supporting said grippers, means effective to cause the stationary guides and supporting said grip,-

pers,'means effective to cause the grippers. to grasp the sald neck when the carriage and said plunger and arm reach predetermined positions, and means for moving said car riage relatively to said plunger to strip the tube therefrom and means for releasing the neck of the tube from said grippers and means for imparting an ejecting movement to the tube transversely of the direction of movement of the carriage. 3. A press for making collapsible tubesof soft metal comprising a laterally swlngmg arm carrying a plunger arranged to be reciprocated longitudinally, grippers adapted to grasp the neck on the extremity of a tube carried by the plunger, a carriage movable along stationary guides and supporting said grippers, means actuated by the movement of said arm eiiective to cause said grippers to grasp said neck, meansfor moving the carriage longitudinally of said plunger,

means for opening said grippers, and a knockout device for positively ejecting the tube'from said grippers. I

4:. A press for making collapsible tubes of soft metal comprising a laterally swinging arm carrying a plunger arranged to be re ciprocated longitudinally, grippers adapted to grasp the neck on the extremity of a tube carried by the plunger, a carriage movable along stationary guides and supporting said gr1ppers,hous1ng supporting said guides and enclosing said carriage, means for moving 1 said carriage longitudinaly of said housing, a grlpper operating bar plvotally mounted on said housing and means responslve to movements of said swinging arm for causing said bar to actuate said grippers.

5. A press for making collapsible tubes of soft metal comprising a laterally swinging arm carrymg a plunger arranged to be reciprocated longltudinaly, grippers adapted to grasp the neck on the extremity of a tube carried by the plunger, a carriage movable along stationary guides and supporting said grippers, housing supporting said guides and enclosing said carriage, means for moving said carriage longitudinally of said housing, a gripper operating bar pivotally mounted on said housing'and means responsive to movements of said swinging arm for causing said bar to actuate said grippers in one direction, yieldable members eliective to ao Gil 1,sse,45s

tuate said grippers in the opposite direction, means effective to open said grippers after the tube is stripped from said plunger and means for positively ejecting the tube from the grippers.

6. A press for making collapsible tubes of soft metal comprising a laterally swinging arm carrying a plun er arran ed to be reciprocated longitudinally, grippers adapted to grasp the neck on the extremity of a tube carried by the plunger, a stationary support, a carriage movable longitudinally thereof to which said grippers are pivoted, resilient means eflective to open said grippers upon the up-stroke of said carriage, a gripper actuating bar movable in response to movement of said arm and effective to flex said resilient members and thus close the grippers about the neck of the tube, means for opening said grippers aproximately upon the completion of the down-stroke of said carriage and means for positively ejecting the tube from the grippers.

7. A press for making collapsible tubes of soft metal comprising a laterally swinging arm carrying a plunger arranged to be reciprocated longitudinally, grippers adapted to grasp the neck on the extremity of a tube carried by the plunger, a carriage movable along stationary guides and supporting said grippers, fixed resilient members for automatically opening said grippers upon the upstroke of said carriage, a gripper actuating bar effective to close the grippers and hold them closed during part of the down-stroke of said carriage, means for opening the grippers approximately upon the completion of the down-stroke of the carriage and a fixed member adapted to pass between the grippers upon their down stroke to eject the tube.

8. A press for making collapsible tubes of soft metal comprising a laterally swinging arm carrying a plunger arranged to be reciprocated longitudinally, grippers adapted to grasp the neck on the extreimty of a tube carried by the plunger, a carriage movable along stationary guides and supporting said grippers, fixed resilient members for automatically opening said grippers upon the upstroke of said carriage, a gripper actuating bar eflective to close the grippers and hold them closed during part of the down-stroke of said carriage, means for opening the grippers approximately upon the completion of the clown-stroke of the carriage and a movable knock-ofi member to influence the direction in which the tube falls when released by the grippers.

9. A press for making collapsible tubes of soft metal comprising a laterally swinging arm carrying a plunger arranged to be reciprocated longitudinally, grippers adapted to grasp the neck on the extremity of a tube carried by the plunger, acarriage movable along stationary guides and supporting said grippers, fixed resilient members for automaticallyppening said grippers upon the upstroke of said carriage, a gripper actuating bar effective to close the grippers and hold them closed during part of the down-stroke of said carriage, means for opening the grippers approximately upon the completion of the down-stroke of the carriage and a fixed member adapted to pass between the grippers upon their down stroke to eject the tube and a movable knock-ofl' member actuated in response to the movement of the carriage and eflective to influence the direction in which the tube falls when released by the grippers.

10. In an apparatus of the character described, a plunger and means for stripping an article formed thereon comprising grippers which bite into the article, means for moving the grippers, means for periodically opening and closing them, and means for positively ejecting the article when released by the grippers.

11. In an apparatus of the character described a plunger and means for stripping an article formed thereon comprising grippers which embrace the article, means for moving the grippers longitudinally of the plunger, means for periodically opening and closing them and means for influencing the direction in which the tube will fall by gravity when released by the grippers.

12. In an apparatus of the character described a plunger and means for stripping an article formed thereon comprising grippers, which bite into the article, means for moving the grippers, means for periodically opening and closing them, and means for slidably supporting the grippers, a housing having guides coacting with said slidable supporting means, and means for adjusting the relationship between said housing and said plunger.

In witness whereof, I have hereunto signed my name.

PAUL WITTE. 

